1. Field of the Invention
The present invention relates generally to improvements in equipment monitoring systems and more particularly, pertains to new and improved gas monitor system wherein the combustible or flammable gases of the exhaust gas is monitored on a real time basis to continuously adjust the damper in the exhaust flue of the monitored equipment to control the concentration of the gases. Further, the system checks its own calibration on regular intervals to ensure that the system is not out of calibration or that the sensor has not suffered from a sensitivity decrease.
2. Description of the Prior Art
Those concerned with the control of the combustible or flammable gases in monitored equipment have long recognized the need for a reliable and accurate gas monitor system. The present invention fills this need.
Prior systems failed to accurately and reliably maintain the concentration of combustible or flammable gases in a prescribed range on a real time basis and failed to regularly check the calibration of the gas monitor system on a regular interval.
The prior art systems upon sensing a high concentration of combustible or flammable gases in the monitored equipment would operate to shut down the equipment to eliminate an explosive condition. When a shut-down in the monitored system occurred such as in a heating system, it was time consuming and expensive to restart the heating cycle of the system. Other prior art systems would sense a high concentration of combustible flammable gases, and upon sensing an explosive condition, would open a damper in the exhaust flue of the monitored equipment to exhaust the gases in the chamber. Other prior art systems would operate on an open-loop system permitting only minimal control of the damper of the monitored equipment. This invention fills the need by providing a closed-loop system to continually adjust the damper on a real time basis as the monitored equipment operates to maintain the concentration of combustible or flammable gases in the monitored equipment within a particular desired percentage range.
Other prior art systems would fail to calibrate gas monitor systems on a regular interval basis. The system was usually calibrated at installation and possibly on a periodic preventative maintenance basis, but depending upon usage and other factors including environmental operating conditions, the systems would sometimes go out of calibration resulting in dangerous amounts of combustible or flammable gases which would collect in the monitored equipment. This invention utilizes calibrating and timing circuitry to periodically discharge a measured amount of calibration gas to check the calibration of the gas monitor system.